Alert archive / Minnesota / Severe Thunderstorm Watches in 2014

Severe Thunderstorm Watch 428

July 21, 201430 counties in Minnesota; Burnett County, Douglas County, Polk County, Wisconsin

The Storm Prediction Center issued this severe thunderstorm watch at Jul 21, 2014, 9:24 PM CDT for 30 counties in Minnesota; Burnett County, Douglas County, Polk County, Wisconsin. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Jul 21, 2014, 9:24 PM CDT (02:24 UTC)
Expired: Jul 22, 2014, 3:20 AM CDT
In force: 6 hr
Issued by: the Storm Prediction Center
Largest hail expected: 1.5 in
Strongest gust expected: 65 kt

All 33 counties

Aitkin County, MN, Becker County, MN, Beltrami County, MN, Benton County, MN, Carlton County, MN, Cass County, MN, Chisago County, MN, Clearwater County, MN, Cook County, MN, Crow Wing County, MN, Douglas County, MN, Grant County, MN, Hubbard County, MN, Isanti County, MN, Itasca County, MN, Kanabec County, MN, Koochiching County, MN, Lake County, MN, Lake of the Woods County, MN, Mille Lacs County, MN, Morrison County, MN, Otter Tail County, MN, Pine County, MN, Pope County, MN, Saint Louis County, MN, Sherburne County, MN, Stearns County, MN, Stevens County, MN, Todd County, MN, Wadena County, MN, Burnett County, WI, Douglas County, WI, Polk County, WI

The radar

The Duluth radar (KDLH), 152 km from the middle of the area, began a volume at 02:25 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes: 20%
One or more EF2 to EF5 tornadoes: 5%
Ten or more severe wind reports: 60%
One or more gusts of 65 knots or more: 40%
Ten or more severe hail reports: 20%
One or more hailstones of 2 inches or more: 10%
Six or more combined severe hail and wind reports: 90%

Warnings issued inside it

21 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

Issued	Product	Office	Counties	Lasted
Jul 21, 10:01 PM CDT	Severe Thunderstorm Warning	FGF	Becker, Beltrami, Clearwater, Hubbard, Lake of the Woods, Mahnomen and 3 more	59 min
Jul 21, 10:13 PM CDT	Severe Thunderstorm Warning	MPX	Stevens	47 min
Jul 21, 10:24 PM CDT	Severe Thunderstorm Warning	DLH	Cass, Itasca, Koochiching	51 min
Jul 21, 10:33 PM CDT	Severe Thunderstorm Warning	MPX	Douglas, Pope	42 min
Jul 21, 11:08 PM CDT	Severe Thunderstorm Warning	MPX	Douglas, Pope, Stearns, Todd	67 min
Jul 21, 11:11 PM CDT	Severe Thunderstorm Warning	DLH	Cass, Itasca, Koochiching, Saint Louis	64 min
Jul 21, 11:16 PM CDT	Severe Thunderstorm Warning	DLH	Cass, Crow Wing	44 min
Jul 21, 11:36 PM CDT	Severe Thunderstorm Warning	MPX	Benton, Morrison, Stearns	39 min
Jul 21, 11:57 PM CDT	Severe Thunderstorm Warning	DLH	Aitkin, Cass, Crow Wing, Itasca	48 min
Jul 22, 12:11 AM CDT	Severe Thunderstorm Warning	DLH	Itasca, Koochiching, Saint Louis	49 min
Jul 22, 12:36 AM CDT	Severe Thunderstorm Warning	DLH	Aitkin, Carlton, Pine, Saint Louis	24 min
Jul 22, 12:47 AM CDT	Severe Thunderstorm Warning	MPX	Kanabec, Mille Lacs	58 min
Jul 22, 12:59 AM CDT	Severe Thunderstorm Warning	DLH	Carlton, Pine, Saint Louis	46 min
Jul 22, 1:03 AM CDT	Severe Thunderstorm Warning	DLH	Pine	42 min
Jul 22, 1:40 AM CDT	Severe Thunderstorm Warning	DLH	Lake, Saint Louis	37 min
Jul 22, 1:42 AM CDT	Severe Thunderstorm Warning	DLH	Pine	48 min
Jul 22, 1:43 AM CDT	Severe Thunderstorm Warning	DLH	Cook, Lake	35 min
Jul 22, 2:11 AM CDT	Severe Thunderstorm Warning	DLH	Cook, Lake	49 min
Jul 22, 2:14 AM CDT	Severe Thunderstorm Warning	DLH	Cook, Lake	46 min
Jul 22, 2:23 AM CDT	Severe Thunderstorm Warning	DLH	Ashland, Bayfield, Burnett, Iron, Price, Sawyer and 1 more	41 min
Jul 22, 2:42 AM CDT	Severe Thunderstorm Warning	DLH	Cook	33 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

International Fa, MN (KINL), launched 00:00Z, 2.4 hours before the alert went out and 141 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 3234 J/kg
Mixed-layer CIN: -14 J/kg
Mixed-layer LCL: 1331 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 22 m²/s²
0-3 km storm-relative helicity: 98 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 3.2

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 21, 8:47 PM CDT	Mesoscale Discussion	SPC	Aitkin, Becker, Beltrami, Benton, Carlton, Cass and 23 more	58 min
Jul 21, 9:08 PM CDT	Mesoscale Discussion	SPC	Big Stone, Clay, Kittson, Mahnomen, Marshall, Norman and 6 more	97 min
Jul 21, 11:44 PM CDT	Mesoscale Discussion	SPC	Aitkin, Anoka, Benton, Carlton, Cass, Chisago and 16 more	91 min
Jul 22, 12:46 AM CDT	Mesoscale Discussion	SPC	Aitkin, Benton, Carlton, Chisago, Cook, Isanti and 6 more	59 min
Jul 22, 1:20 AM CDT	Severe Thunderstorm Watch	SPC	Ashland, Bayfield, Florence, Forest, Iron, Oneida and 4 more	6 hr
Jul 22, 4:10 AM CDT	Mesoscale Discussion	SPC	Iron, Oneida, Price, Sawyer, Vilas, Washburn	95 min
Jul 22, 5:54 PM CDT	Mesoscale Discussion	SPC	Dane, Dodge, Green, Jefferson, Kenosha, Milwaukee and 7 more	2 hr

Nearby

Severe Thunderstorm Watches in Minnesota, 2014 Severe Thunderstorm Watches in Wisconsin, 2014 Every severe thunderstorm watch in 2014

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.